An air clarifying apparatus is intended to maintain a comfortable indoor environment by carrying out air circulation using a fan while filtering dirty indoor air. In recent years, attention is paid to the effects of negative ions, such as an effect of making people refreshing, a blood purification effect, a mental stabilization effect and a fatigue recovery effect (these are hereafter generally referred to as a relaxation effect). Air clarifying apparatuses equipped with a negative ion generation function are being used widely. On the other hand, sterilizing apparatuses and bacteria elimination apparatuses that use the sterilizing effect of ozone are well known. However, the concentration of ozone that is used for this purpose is usually set to approximately 1% or more, for example, and this concentration is harmful to the human body. Hence, in air clarifying apparatuses, ozone has not been used positively for the purpose of sterilizing indoor air using the sterilizing effect of ozone or for an antibacterial purpose, in other words, for the purpose of suppressing bacterial growth, but rather has been eliminated as a harmful substance.
For example, Japanese Patent Application Laid-Open No. 2001-259470 discloses an example of an air clarifying apparatus in which ozone generated together with negative ions by high-voltage discharge is decomposed and eliminated using a catalyst. Japanese Patent Application Laid-Open No. 2000-140688 discloses examples of an air clarifying apparatus and an air-conditioning apparatus in which ozone generated secondarily together with negative ions by high-voltage discharge is used effectively for sterilization inside the apparatuses. In addition, Journal of the Society for Antibacterial and Antifungal Agents, Japan, Vol. 27, No. 11, p. 713 to 722 (hereafter referred to as paper 1) and Food processing and development (SHOKUHIN TO KAIHATSU), Vol. 33, No. 10, p. 17 to 21 (hereafter referred to as paper 2) disclose reports that discuss the effect of sterilization that is enhanced by the combined use of ozone and negative ions, but do not mention at all the coexistence of negative ions and ozone both having low concentrations not adversely affecting the human body and indoor equipment.
The present invention is achieved by taking a hint from the reports of the above-mentioned papers. More specifically, the present invention is intended to create a comfortable indoor environment by fully utilizing a relaxation effect obtained by negative ions and by allowing the negative ions to coexist with ozone so that the sterilizing effect or the antibacterial effect of an air clarifying apparatus is enhanced by the sterilizing power of the ozone.